1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25 #ifndef SHARE_VM_RUNTIME_MUTEXLOCKER_HPP
26 #define SHARE_VM_RUNTIME_MUTEXLOCKER_HPP
27
28 #include "memory/allocation.hpp"
29 #include "runtime/mutex.hpp"
30
31 // Mutexes used in the VM.
32
33 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code
34 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary
35 extern Mutex* Module_lock; // a lock on module and package related data structures
36 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
37 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer
38 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment
39 extern Mutex* JNIGlobalAlloc_lock; // JNI global storage allocate list lock
40 extern Mutex* JNIGlobalActive_lock; // JNI global storage active list lock
41 extern Mutex* JNIWeakAlloc_lock; // JNI weak storage allocate list lock
42 extern Mutex* JNIWeakActive_lock; // JNI weak storage active list lock
43 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list
44 extern Mutex* ResolvedMethodTable_lock; // a lock on the ResolvedMethodTable updates
45 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers
46 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers
47 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
48 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data
49 extern Monitor* Heap_lock; // a lock on the heap
50 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap
51 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary
52 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary
53 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs
54 extern Mutex* SymbolTable_lock; // a lock on the symbol table
55 extern Mutex* StringTable_lock; // a lock on the interned string table
56 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue
57 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table
58 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx
59 extern Mutex* MethodData_lock; // a lock on installation of method data
60 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info
61 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
62 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table
63 extern Monitor* CGCPhaseManager_lock; // a lock to protect a concurrent GC's phase management
64 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute
65 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate
66 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction
67 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
68 // (also used by Safepoints too to block threads creation/destruction)
69 extern Monitor* CGC_lock; // used for coordination between
70 // fore- & background GC threads.
71 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
72 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc
73 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q
74 // buffer free list.
75 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q
76 // completed buffer queue.
77 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB
78 // queue shared by
79 // non-Java threads.
80
81 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q
82 // buffer free list.
83 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q
84 // completed buffer queue.
85 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card
86 // queue shared by
87 // non-Java threads.
88 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list.
89 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list.
90 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops.
91 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
92 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
93 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
94 extern Monitor* Compilation_lock; // a lock used to pause compilation
95 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
96 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
97 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
98 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays
99 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
100 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
101 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
102 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
103 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
104 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues
105
106 #ifndef PRODUCT
107 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
108 #endif // PRODUCT
109 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
110 extern Mutex* Debug2_lock; // down synchronization related bugs!
111 extern Mutex* Debug3_lock;
112
113 extern Mutex* RawMonitor_lock;
114 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
115 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
116 extern Mutex* ParkerFreeList_lock;
117 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
118
119 extern Mutex* FreeList_lock; // protects the free region list during safepoints
120 extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list
121 extern Mutex* OldSets_lock; // protects the old region sets
122 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
123
124 extern Mutex* Management_lock; // a lock used to serialize JVM management
125 extern Monitor* Service_lock; // a lock used for service thread operation
126 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
127 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
128 extern Monitor* ThreadHeapSampler_lock; // protects the static data for initialization.
129
130 #if INCLUDE_TRACE
131 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
132 extern Monitor* JfrMsg_lock; // protects JFR messaging
133 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
134 extern Mutex* JfrStream_lock; // protects JFR stream access
135 #endif
136
137 #ifndef SUPPORTS_NATIVE_CX8
138 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
139 #endif
140
141 // A MutexLocker provides mutual exclusion with respect to a given mutex
142 // for the scope which contains the locker. The lock is an OS lock, not
143 // an object lock, and the two do not interoperate. Do not use Mutex-based
144 // locks to lock on Java objects, because they will not be respected if a
145 // that object is locked using the Java locking mechanism.
146 //
147 // NOTE WELL!!
148 //
149 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
150 // and friends constructors do a fence, a lock and an acquire *in that
151 // order*. And that their destructors do a release and unlock, in *that*
152 // order. If their implementations change such that these assumptions
153 // are violated, a whole lot of code will break.
154
155 // Print all mutexes/monitors that are currently owned by a thread; called
156 // by fatal error handler.
157 void print_owned_locks_on_error(outputStream* st);
158
159 char *lock_name(Mutex *mutex);
160
161 class MutexLocker: StackObj {
162 private:
163 Monitor * _mutex;
164 public:
165 MutexLocker(Monitor * mutex) {
166 assert(mutex->rank() != Mutex::special,
167 "Special ranked mutex should only use MutexLockerEx");
168 _mutex = mutex;
169 _mutex->lock();
170 }
171
172 // Overloaded constructor passing current thread
173 MutexLocker(Monitor * mutex, Thread *thread) {
174 assert(mutex->rank() != Mutex::special,
175 "Special ranked mutex should only use MutexLockerEx");
176 _mutex = mutex;
177 _mutex->lock(thread);
178 }
179
180 ~MutexLocker() {
181 _mutex->unlock();
182 }
183
184 };
185
186 // for debugging: check that we're already owning this lock (or are at a safepoint)
187 #ifdef ASSERT
188 void assert_locked_or_safepoint(const Monitor * lock);
189 void assert_lock_strong(const Monitor * lock);
190 #else
191 #define assert_locked_or_safepoint(lock)
192 #define assert_lock_strong(lock)
193 #endif
194
195 // A MutexLockerEx behaves like a MutexLocker when its constructor is
196 // called with a Mutex. Unlike a MutexLocker, its constructor can also be
197 // called with NULL, in which case the MutexLockerEx is a no-op. There
198 // is also a corresponding MutexUnlockerEx. We want to keep the
199 // basic MutexLocker as fast as possible. MutexLockerEx can also lock
200 // without safepoint check.
201
202 class MutexLockerEx: public StackObj {
203 private:
204 Monitor * _mutex;
205 public:
206 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
207 _mutex = mutex;
208 if (_mutex != NULL) {
209 assert(mutex->rank() > Mutex::special || no_safepoint_check,
210 "Mutexes with rank special or lower should not do safepoint checks");
211 if (no_safepoint_check)
212 _mutex->lock_without_safepoint_check();
213 else
214 _mutex->lock();
215 }
216 }
217
218 ~MutexLockerEx() {
219 if (_mutex != NULL) {
220 _mutex->unlock();
221 }
222 }
223 };
224
225 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
226 // a possibly null Monitor, and allows wait/notify as well which are
227 // delegated to the underlying Monitor.
228
229 class MonitorLockerEx: public MutexLockerEx {
230 private:
231 Monitor * _monitor;
232 public:
233 MonitorLockerEx(Monitor* monitor,
234 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
235 MutexLockerEx(monitor, no_safepoint_check),
236 _monitor(monitor) {
237 // Superclass constructor did locking
238 }
239
240 ~MonitorLockerEx() {
241 #ifdef ASSERT
242 if (_monitor != NULL) {
243 assert_lock_strong(_monitor);
244 }
245 #endif // ASSERT
246 // Superclass destructor will do unlocking
247 }
248
249 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
250 long timeout = 0,
251 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
252 if (_monitor != NULL) {
253 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
254 }
255 return false;
256 }
257
258 bool notify_all() {
259 if (_monitor != NULL) {
260 return _monitor->notify_all();
261 }
262 return true;
263 }
264
265 bool notify() {
266 if (_monitor != NULL) {
267 return _monitor->notify();
268 }
269 return true;
270 }
271 };
272
273
274
275 // A GCMutexLocker is usually initialized with a mutex that is
276 // automatically acquired in order to do GC. The function that
277 // synchronizes using a GCMutexLocker may be called both during and between
278 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
279 // if GC is in progress (since the mutex is already held on its behalf.)
280
281 class GCMutexLocker: public StackObj {
282 private:
283 Monitor * _mutex;
284 bool _locked;
285 public:
286 GCMutexLocker(Monitor * mutex);
287 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
288 };
289
290
291
292 // A MutexUnlocker temporarily exits a previously
293 // entered mutex for the scope which contains the unlocker.
294
295 class MutexUnlocker: StackObj {
296 private:
297 Monitor * _mutex;
298
299 public:
300 MutexUnlocker(Monitor * mutex) {
301 _mutex = mutex;
302 _mutex->unlock();
303 }
304
305 ~MutexUnlocker() {
306 _mutex->lock();
307 }
308 };
309
310 // A MutexUnlockerEx temporarily exits a previously
311 // entered mutex for the scope which contains the unlocker.
312
313 class MutexUnlockerEx: StackObj {
314 private:
315 Monitor * _mutex;
316 bool _no_safepoint_check;
317
318 public:
319 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
320 _mutex = mutex;
321 _no_safepoint_check = no_safepoint_check;
322 _mutex->unlock();
323 }
324
325 ~MutexUnlockerEx() {
326 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
327 _mutex->lock_without_safepoint_check();
328 } else {
329 _mutex->lock();
330 }
331 }
332 };
333
334 #ifndef PRODUCT
335 //
336 // A special MutexLocker that allows:
337 // - reentrant locking
338 // - locking out of order
339 //
340 // Only to be used for verify code, where we can relax out dead-lock
341 // detection code a bit (unsafe, but probably ok). This code is NEVER to
342 // be included in a product version.
343 //
344 class VerifyMutexLocker: StackObj {
345 private:
346 Monitor * _mutex;
347 bool _reentrant;
348 public:
349 VerifyMutexLocker(Monitor * mutex) {
350 _mutex = mutex;
351 _reentrant = mutex->owned_by_self();
352 if (!_reentrant) {
353 // We temp. disable strict safepoint checking, while we require the lock
354 FlagSetting fs(StrictSafepointChecks, false);
355 _mutex->lock();
356 }
357 }
358
359 ~VerifyMutexLocker() {
360 if (!_reentrant) {
361 _mutex->unlock();
362 }
363 }
364 };
365
366 #endif
367
368 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP